#coding:utf-8

def main():
  N = input()
  n = list(N)
  print(max(al_list(n)))


def al_list(n):
  al = []
  al.append(int(''.join(n)))
  origin = list(n)
  for i in range(len(n)):
    for j in range(i+1,len(n)):
      n = list(origin)
      n[i], n[j] = n[j], n[i]
      al.append(int(''.join(n)))
  return al
  

if __name__ == '__main__':
  main()